Software Engineer II - Organizations

Klaviyo•Boston, MA

22h•Onsite

About The Position

The Core Infrastructure - Identity & Organizations (Core IO) pillar owns the foundational substrate for identity, access, organizations, and platform integrity at Klaviyo. We manage the critical path of the user journey from login, to enforcing permissions, to operating within the correct organization and regional context so that the rest of the platform can move fast and stay secure. Within Core IO, the Organizations team owns the data model and platform APIs that define what a customer's account looks like inside Klaviyo and what it is allowed to do. We build and operate the services that power multi-account experiences, enterprise account hierarchies, organization-level lifecycle and policy enforcement, and the onboarding and settings layer for every customer. Our systems are foundational dependencies for nearly every product team at Klaviyo. Why this role is exciting: Shape Klaviyo's enterprise organization platform: We are designing and shipping the multi-level organization hierarchy that large, multi-brand enterprise customers need-platform work that will define how Klaviyo serves its most strategic customers for years to come. Unlock global scale and compliance: Your work directly supports Klaviyo's international expansion and compliance requirements-including Data Residency for customers worldwide Platform-level leverage: The organization and account services your team owns are called by analytics, billing, messaging, identity, and nearly every product surface. Well-designed APIs or data models from this team multiplies engineering velocity across the company. Deep domain and systems learning: You will get hands-on exposure to distributed systems, complex data modeling, tenant and hierarchy management, organization-level policy evaluation, and full-stack development across Go services, Python APIs, and React frontends-with mentorship and meaningful ownership.

Requirements

2-5+ years of professional software engineering experience.
Proficiency in at least one of Python, Go, or TypeScript/JavaScript , and comfort working on backend and/or service-oriented systems, including web services or APIs backed by relational databases and/or caches (e.g., MySQL, Postgres, Redis).
Strong intuition for data modeling and API design , including thinking through correctness, backward compatibility, and how downstream consumers will use your interfaces.
Exposure to CI/CD pipelines and modern development workflows (code review, testing, deployments, on-call participation or support).
You are a mid-level software engineer who has shipped and supported production systems, and who is excited about data modeling, platform APIs, and building infrastructure that other engineers depend on.
Experienced systems builder: You have 2-5+ years of professional software engineering experience, including building and operating backend or full-stack services in production.
Strong fundamentals and debugging skills: You are comfortable reasoning about data models, API design, concurrency, and failure modes, and you can dig through logs, metrics, and traces to identify root causes and implement systemic fixes.
Domain modeling and platform mindset: You enjoy modeling complex real-world entities-accounts, organizations, hierarchies, lifecycle states-as well-typed data structures and APIs that other teams can rely on. You like building reusable services and internal libraries that raise the floor for correctness and consistency across the organization.
Breadth across the stack: You are comfortable contributing across backend services, internal APIs, and product-facing frontend surfaces. You may have a home base in one layer, but you are not intimidated by the others.
Ownership and collaboration: You take responsibility for outcomes, not just code. You are comfortable driving a project end-to-end, partnering with teams across the pillar, and communicating trade-offs clearly in design docs and pull requests.
You've already experimented with AI in work or personal projects, and you're excited to dive in and learn fast. You're hungry to responsibly explore new AI tools and workflows.

Nice To Haves

Experience with hierarchical or graph-structured data models (e.g., tree structures, parent-child relationships, org charts) and the consistency and performance challenges they introduce.
Familiarity with multi-tenancy patterns in SaaS products, including data isolation, tenant-scoped configuration, and cross-tenant operations.
Working with cloud-native infrastructure (AWS, Kubernetes, Terraform, or similar) and building services designed to run at scale.
Exposure to compliance or data residency requirements (GDPR, regional data isolation) and how they shape platform and data architecture decisions.
Familiarity with observability stacks (Grafana, Datadog, Splunk) and using them to drive reliability improvements.
Interest or experience in adjacent Core IO domains like Identity & Access Management or Platform Anti-Abuse, especially where they intersect with account security, access control, and organization-level policy.

Responsibilities

Own features end-to-end across design, implementation, rollout, and observability for core account and organization capabilities such as hierarchy management, account lifecycle, organization-scoped settings, and multi-account experiences for agencies and enterprise customers.
Help build and evolve the organization hierarchy platform: Design and implement the APIs, data models, and services that represent multi-level enterprise structures, including hierarchy traversal and event-driven lifecycle for downstream systems.
Contribute to organization-level policy infrastructure: Help design and extend the system that determines what an account is capable of-translating organization status, plan entitlements, and compliance requirements into clear, auditable answers for the rest of the platform.
Support Data Residency and compliance initiatives: Build organization-aware primitives that help Klaviyo route data and enforce region-specific and compliance requirements at the account level.
Contribute to service extraction and platform migration: Help move core account and organization logic from our legacy monolith into dedicated services and client libraries-unlocking faster iteration and stronger contracts for product teams.
Define and refine standards for how the rest of the platform interacts with organization data-API contracts, event schemas, audit logging patterns, and integration conventions-so teams across Klaviyo don't solve these problems independently.
Collaborate closely with partner teams: Work with Identity & Access Management (IAM) to ensure organization policies and identity permissions compose cleanly, and with Platform Integrity & Protection (PAA) on lifecycle controls that support account security and anti-abuse.
Build and maintain shared contracts and SDKs so other product teams can consume organization data and policies safely, making correct usage the path of least resistance.
Improve reliability and performance of organization services by instrumenting metrics and alerts, debugging production issues, and contributing to on-call rotations and incident reviews.